Plant for mono-incineration of sewage sludge in Hannover-Lahe: HUBER Disc Dryer RotaDry® ready for hot commissioning

Using a heavy-duty crane, the two disc dryers, each weighing around 63 tonnes, were unloaded from the heavy-duty transporters on site in November 2021 and lifted directly into the building onto the prepared level. They will be used in the Hannover-Lahe sewage sludge mono-incineration plant (KVA) as pre-dryers for processing the sewage sludge into fuel. Shortly afterwards, the fluidised bed furnace and turbine were also lifted into place and the missing steel structure was completed.

Thermal drying for further utilisation of the sewage sludge: environmentally friendly heat for around 5,000 households

The HUBER Disc Dryer RotaDry® units dry the dewatered sewage sludge to such an extent that it can be utilised autothermally (i.e. without external heat or energy input) as fuel in the fluidized bed incinerator. The steam generated in the boiler is used both to produce electricity to cover the plant's own electrical needs and to heat the dryers. The vapours produced (steam) are condensed in a vapour condenser, the resulting heat is used to feed the district heating network. The environmentally friendly heat is then available to around 5,000 households.

Successful cold commissioning in 2022

A successful milestone in the project: In November 2022, the cold commissioning with signal check and direction of rotation tests took place. During the cold commissioning, the two rotors, which weigh several tonnes, were also set in motion gently for the first time. After completion of cold commissioning, a comprehensive training of the operating personnel by the responsible HUBER process engineer took place.

Outlook: hot commissioning and start-up

The service team will soon start the hot commissioning and start-up of the two HUBER Disc Dryer RotaDry® units. The dryers will then be exposed to steam for the first time and heated up in a controlled manner. Following the successful hot commissioning, sewage sludge can be dried and conveyed to the fluidized bed incinerator for the first time.